Struct Optional

pub struct Optional<T>(pub T);

Wrapper for ASN.1 optionals fields

Wrapped type has to implement the Default trait to be deserializable (on deserialization failure a default value is returned).

Examples:

use picky_asn1::wrapper::{Optional, ExplicitContextTag0};
use serde::{Serialize, Deserialize};

#[derive(Serialize, Deserialize, Debug, PartialEq)]
struct MyWrapper(u8);

impl Default for MyWrapper {
    fn default() -> Self {
        Self(10)
    }
}

#[derive(Serialize, Deserialize, Debug, PartialEq)]
struct ComplexType {
    // skip if default to reduce encoded size
    #[serde(skip_serializing_if = "optional_field_is_default")]
    optional_field: Optional<MyWrapper>,
    // behind application tag 0 to distinguish from optional_field that is a ASN.1 integer too.
    explicit_field: ExplicitContextTag0<u8>,
}

fn optional_field_is_default(wrapper: &Optional<MyWrapper>) -> bool {
    wrapper.0 == MyWrapper::default()
}

let complex_type = ComplexType {
    optional_field: MyWrapper::default().into(),
    explicit_field: 5.into(),
};

let buffer = [
    0x30, 0x05, // sequence
    // optional field isn't present
    0xA0, 0x03, 0x02, 0x01, 0x05, // explicit field
];

let encoded = picky_asn1_der::to_vec(&complex_type).expect("couldn't serialize");
assert_eq!(
    encoded,
    buffer,
);

let decoded: ComplexType = picky_asn1_der::from_bytes(&buffer).expect("couldn't deserialize");
assert_eq!(
    decoded,
    complex_type,
);

Tuple Fields

0: T

Implementations

impl<T> Optional<T>

where T: Default + PartialEq,

pub fn is_default(&self) -> bool

Trait Implementations

impl<T: Clone> Clone for Optional<T>

fn clone(&self) -> Optional<T>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Debug> Debug for Optional<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T: Default> Default for Optional<T>

fn default() -> Self

Returns the “default value” for a type.

impl<T> Deref for Optional<T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<T> DerefMut for Optional<T>

fn deref_mut(&mut self) -> &mut Self::Target

Mutably dereferences the value.

impl<'de, T> Deserialize<'de> for Optional<T>

where T: Deserialize<'de> + Default,

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<T> From<T> for Optional<T>

fn from(wrapped: T) -> Self

Converts to this type from the input type.

impl<T: Hash> Hash for Optional<T>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<T> PartialEq<T> for Optional<T>

where T: PartialEq,

fn eq(&self, other: &T) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T: PartialEq> PartialEq for Optional<T>

fn eq(&self, other: &Optional<T>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T: PartialOrd> PartialOrd for Optional<T>

fn partial_cmp(&self, other: &Optional<T>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T> Serialize for Optional<T>

where T: Serialize,

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl<T: Eq> Eq for Optional<T>

impl<T> StructuralPartialEq for Optional<T>